Sound waves vibrate more than just our eardrums, they can also make visual art!

Paul Andersen explains how plants use hormones to respond to their environment. The following hormones are detailed; auxin, cytokinins, gibberelins, abscisic acid and ethylene.

Even a death-defying magician has to start somewhere. High-wire artist Philippe Petit takes you on an intimate journey from his first card trick at age 6 to his tightrope walk between the Twin Towers.

In this video Paul Andersen explains how the wavelength of a standing wave is determined by the boundary length and frequency of the wave. The fundamental frequency has a wavelength double the boundary length. Harmonics are built on...

We can all appreciate pretty shiny things, but what makes them shiny?

When you flip a coin to make a decision, there's an equal chance of getting heads and tails. But what if you flip the coin repeatedly, so that one option would win as soon as two heads showed up in a row, and another would win as soon as...

In this video Paul Andersen explains how Newton's Third Law applies to all objects. When an object applies a force to another object (Action) and equal and opposite force (Reaction) is applied to the original object. Several scenarios...

In this video Paul Andersen details the important structures and functions of the integumentary system. The integumentary system includes the skin, hair and nails in humans.

We have learned over the past few weeks that gases have real-life constraints on how they move here in the non-ideal world. As with most things in chemistry (and also in life) how a gas moves is more complex than it at first...

Mr. Andersen explains how sound waves are created and perceived. A brief discussion of pitch and loudness are included. A generated sound of varying pitches is also included.

From robots to braces to the Mars Rover, see how a special kind of metal called shape memory alloys advance technology in everyday ways that we don't always realize.

Have you ever been so cold that your body shakes really fast? That’s called shivering, and Jessi and Squeaks are going to explain what causes it!

If you’ve ever looked at a frog’s head, you might have noticed that they don’t have external ears. So How do they hear?

In this video Paul Andersen explains how land is developed for human use. Urbanization has occurred through the last century as people have moved to cities in large numbers. Transportation and the arrival of the car have led to urban...

In this video Paul Andersen explains how conservative forces can be used to store potential energy in an object or a system. The work done is equal to the amount of potential energy in the object. The following conservative forces are...

Paul Andersen explains how cells are selectively permeable with the help of their cell membrane. The main constituents of the cell membrane, including cholesterol, glycolipids, glycoproteins, phospholipids, and proteins are included. ...

Climate change is a big problem, but could we solve it by giving the earth a little nudge?

In this video Paul Andersen explains how you can use the Gibbs Free Energy equation to determine if a process is spontaneous or not spontaneous. If the _G is less than zero the process is spontaneous. If the _G is greater than zero the...

How do we design the most efficient machines and processes? Today we’ll try to figure that out as we discuss heat & work, reversibility & irreversibility, and how to use efficiency to measure a system.

Paul Andersen starts this video with a description of the respiratory surface. He explains how worms, insects, fish and mammals take in oxygen and release carbon dioxide. He then tours the major organs of the respiratory system; from...

Today on Crash Course Astronomy, Phil invites you to head outside and take a look at all the incredible things you can see with your naked eye.

You probably won't get stuck in quicksand. But if you do, you can use physics to get yourself out.

You know you’ve wondered. Do fish actually pee? And what does that make the ocean… one big toilet?

As we get ready to watch that big football game that my lawyers tell me I'm not allowed to say the name of, let's celebrate a champion of the bird world: Stealthy and silent owls! Learn how owls fly so silently, how they see in the dark,...